1. Field of the Invention
The present invention relates to an ink set for inkjet printing, and an image forming method.
2. Related Art
An inkjet recording method is a method of performing recording by ejecting an ink in the form of liquid droplets from a number of nozzles provided in an inkjet head, and fixing the ink to the recording medium. In order to obtain high definition images with high resolution, investigations have been made on a fixing agent liquid (also referred to as fixing liquid, treatment liquid, or reaction liquid) containing a compound which accelerates the aggregation of ink, as a technology of rapidly fixing ink to a recording medium.
In this regard, there has been disclosed an image forming system which uses an inkjet ink including a first liquid vehicle, a pigment colorant, and an anionic or neutral latex-containing colloidal suspension, and a fixing agent composition including a second liquid vehicle and a cationic polymer, and this image forming system is considered to be able to form images having durability and smudge resistance (see, for example, Japanese Patent Application Laid-Open (JP-A) No. 2008-105422).
Furthermore, there has been disclosed an inkjet printing system using a fixing agent liquid containing a cationic polymer and an acidic precipitant, and an inkjet ink which includes a pigment having an anionic polymer covalently bonded thereto, and a nonionic surfactant or an anionic binder. This inkjet printing system is considered to be capable of improving (reducing) mottling during printing (see, for example, Japanese Patent No. 4224491 and JP-A No. 2006-159907).